Although there are some unknowns and variations, the broad outlines of the grisly effects of a 10-kiloton groundburst are clear.2 The downtown area, about one mile in radius, would be obliterated. Just outside the area leveled by blast, people wounded by flying debris, fires, and intense radiation would stand little chance of survival. Emergency workers would not get to them be

cause of the intense radiation, and in any event, their burns and acute radiation exposure would require sophisticated and intensive medical care to offer any chance of survival. Further downwind from the detonation point, a plume of radioactive debris would spread. Its shape and size would depend on wind and rain conditions, but within one day, people within five to 10 square miles who did not find shelter or flee within hours would receive lethal radiation doses. This area, for example, could include Brooklyn, New York; northwest Washington, D.C.; or the upper peninsula of San Francisco.

People who were relatively close to the detonation point or who did not shelter themselves from the radiation, which would be most intense on the day of the blast and subside with time, would receive large but varying doses of radiation. If the dose was intense (more than 400 rems), they would get sick and die; if strong but moderate (50-400 rems), they would get sick but probably recover; if moderate (less than 50 rems), they would not notice the effect immediately but would have a greater chance of contracting cancer over their lifetime than if they had received no dose. Because there is little that could be done for those in the area in and around the blast zone, responders would concentrate on minimizing the radiation dose to the population further downwind and preventing chaos among the rest of the population, which would be physically unaffected but traumatized and deprived of whatever utilities and services were located in the affected area.

Here’s the kick in the head:

One might think, given the distinct possibility of a nuclear attack on a U.S. city, that the federal government would have already developed a realistic response plan specific to this scenario that marshals the resources of all the agencies. Remarkably, such a plan does not yet exist, although one is being drafted.

Yes, a lack of preparation is unsettling, but nowhere near as unsettlling as the refsual of the enemies of national security to take seriously the threat. The scope of the devastation that such a one-off could bring makes leaks of the sort discussed below even more unimaginably disgusting.